Description
The rotary R.E. union is a self-contained, self-supporting rotary seal for the leak-proof transfer of fluids such as steam, water, air and oil to and from rotating machine shafts. The type of rotary seal fitted to this model is a Filton® Bellows Seal containing a flexible stainless steel bellows which is self-adjusting, eliminating the maintenance common with conventional packed glands. Rotary sealing is created by relative rotation between extremely flat sealing faces (see item #2 and #4 in diagram above) held in contact by the spring characteristics of the bellows combined with an additional sealing force created by the pressure of the fluid passing through the rotary union. The bearings fitted to the union are standard ball bearings which are supplied with the initial lubrication completed prior to shipping.

Variations of the Stationary Adapter End
There are three variations available:

1) Type B.E. - Single Flow
A single flow union suitable for transferring fluid in to or out of rotating machines.

2) Type S.T. - Double Flow (Stationary Center Tube)
Fitted with an adapter suitable for double flow with a stationary center tube. This gives flow areas through the center tube and annulus. The center tube - provided only if ordered - is fixed to the union end by means of a screw thread (dimension “O”). Flow can pass in through the center tube and return through the annulus or be reversed. For steam applications, the center tube is curved to reach the condensate in the bottom of the cylinder. If the roll neck diameter to length ratio prevents the use of a curved tube, a syphon elbow can be specified instead. See the Accessory Section or contact us for more information about the options available.

3) Type R.S. - Double Flow (Rotary Center Tube)
Fitted with an adapter suitable for a rotating center tube which must be located and driven by the machine. The center tube - provided only if ordered - rotates in a bush. Flow can pass in through the center tube with the return through the annulus or be reversed. The center tube “sealing” system allows for a slight internal leakage between the supply and return lines. If these fluids must not mix, alternate designs are available.

Nominal Size

ROTARY R.E. UNION - Model Dimensions

A, B, N

C

D

E

F

G, P

H

I

O

Q

S

T

U

V

8 (1/4")

G.1/4"

6

117

94

22

11

30

57

M5x0.8

6

4.75/4.72

25

24

44

10 (3/8")

G.3/8"

10

121

97

25

13

30

57

M6x1.0

6

6.35/6.32

25

24

44

15 (1/2")

G.1/2"

13

167

130

29

16

44

83

G.1/8"

6

9.52/9.50

40

38

63

20 (3/4")

G.3/4"

18

173

133

32

19

44

83

G.1/4"

10

12.70/12.672

40

38

63

25 (1")

G.1"

22

197

149

48

22

54

105

G.3/8"

10

15.87/15.85

45

43

83

32 (1-1/4")

G.1-1/4"

30

227

170

51

25

70

121

G.1/2"8

13

19.05/19.02

50

55

95

Note: (i) "G" is the designation for parallel pipe threads to BS.2779 and ISO 228/1.